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preface3
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<H1>Preface to the Third (2000) Edition
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<br>&#32;<br>
A great deal has happened to Plan 9 in the five years since its last release.
Although much of the system will seem familiar, hardly any aspect
of it is unchanged.
The kernel has been heavily reworked;
the graphical environment completely rewritten;
many commands added, deleted, or replaced;
and the libraries greatly expanded.
Underneath, though, the same approach to computing remains:
a distributed system that uses file-like naming to access and
control resources both local and remote.
<br>&#32;<br>
Some of the changes are sweeping:
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<DT><DT>&#32;<DD>
Alef is gone, a casualty of the cost of maintaining multiple languages, compilers,
and libraries in a diverse world,
but its model for processes, tasks, and communication lives on
in a new thread library for C.
<DT><DT>&#32;<DD>
Support for color displays is much more general, building on a new
alpha-blending graphical operator called
<TT>draw</TT>
that replaces the old
<TT>bitblt</TT>.
Plan 9 screens are now, discreetly, colorful.
<DT><DT>&#32;<DD>
A new mechanism called plumbing connects applications together
in a variety of ways, most obviously in the support of multimedia.
<DT><DT>&#32;<DD>
The interfaces to the panoply of rotating storage devices have been
unified and extended,
while providing better support for having Plan 9 coexist with other
operating systems on a single disk.
<DT><DT>&#32;<DD>
Perhaps most important, this release of the system is being done under
an open source agreement, providing cost-free source-level access to the
software.
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<br>&#32;<br>
Plan 9 continues to be the work of many people.
Besides those mentioned in the old preface,
these people deserve particular note:
Russ Cox did much of the work updating the graphics
and creating the new disk and bootstrap model
as well as providing a number of new commands;
David Hogan ported Plan 9 to the Dec Alpha;
and
Sape Mullender wrote the new thread library.
<br>&#32;<br>
Other new contributors include
Bruce Ellis,
Charles Forsyth,
Eric Van Hensbergen,
and
Tad Hunt.
<br>&#32;<br>
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<DL><DT><DD>
<DL><DT><DD>
<DL><DT><DD>
<DL><DT><DD>
<DL><DT><DD>
<DL><DT><DD>
Bell Labs
<br>
Computing Science Research Center
<br>
Murray Hill NJ
<br>
June, 2000

<br>&#32;<br>
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Copyright</A> &#169; 2000 Lucent Technologies Inc.  All rights reserved.
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